diff --git a/lectures/20_hash_tables_I/README.md b/lectures/20_hash_tables_I/README.md
index 23c1409..b2aa04c 100644
--- a/lectures/20_hash_tables_I/README.md
+++ b/lectures/20_hash_tables_I/README.md
@@ -5,9 +5,11 @@
 - Hash Tables, Hash Functions, and Collision Resolution <!--(leetcode 1, 705, 706)-->
 - Performance of: Hash Tables vs. Binary Search Trees
 - Collision resolution: separate chaining vs open addressing
-- STL’s unordered_set (and unordered_map)
+- STL’s unordered_set and unordered_map
 - Using a hash table to implement a set/map
+
   – Hash functions as functors/function objects (leetcode 1451: Rearrange Words in a Sentence)
+
   – Iterators, find, insert, and erase
 
 ## 20.1 Definition: What’s a Hash Table?